Achieving Sustainable Urban Form

Elizabeth Burton, Mike Jenks, Katie Williams

• Publisher: Routledge
• Year: 2013
• ISBN:
  9781136804793
• Edition: 1
• Topic: Architecture
• Subtopic: Urban Planning & Landscaping

Achieving Sustainable Urban Form represents a major advance in the sustainable development debate. It presents research which defines elements of sustainable urban form - density, size, configuration, detailed design and quality - from macro to micro scale. Case studies from Europe, the USA and Australia are used to illustrate good practice within the fields of planning, urban design and architecture.

Part 1
Defining Sustainable Urban Form
Introduction

A prerequisite to achieving sustainable urban form is knowing what it is. To realise the ‘sustainable city’ there has to be a clear and common-held concept of what it will look like, how it will function, and how it will change over time. Until fairly recently, there was some consensus - although there was also considerable scepticism - that compact urban forms offered the most sustainable future. Subsequently, much research has focused on compact versus dispersed settlement patterns. However, this latter research gave rise to questions about the complexities and impacts of a whole range of urban forms. In presenting their findings, researchers argued that relationships previously assumed to exist between urban form and a number of sustainability benefits were either unsubstantiated by fact, or dependent on a range of intervening variables - some of which were far more significant than urban form.

The chapters in Part 1 are examples of this ‘second wave’ of research. Many of them refer to previous research and use the invaluable knowledge it provides as the basis of new studies. The chapters advance the debate by offering more sophisticated analyses and testing of the key elements of urban form: density, compactness, concentration, dispersal, mix of uses, housing type and so on. They offer either new evidence which sheds light on aspects of urban sustainability, or they offer alternative views of what sustainable urban form might be.

The first chapter, by Guy and Marvin, questions whether there is such a thing as ‘sustainable urban form’. The authors take as their starting point the conclusions of the previous volume, The Compact City: A Sustainable Urban Form?, which stated that ‘The search for the ultimate sustainable urban form perhaps now needs to be reoriented to the search for a number of sustainable urban forms which respond to the variety of existing settlement patterns and contexts that have been identified’. The argument that such multiple outcomes could, and should, be pursued is developed. Instead of concentrating on finding one solution, those involved in defining and managing sustainable cities should recognise that a diversity of urban futures are likely to co-exist within a single city. To reach these futures, a number of different and competing pathways could be followed. The authors conclude that identifying these pathways is a challenge to policy makers and researchers alike.

The next two chapters, by Burton and Williams, explore one such pathway: urban compaction. They test, through empirical research, the effects of the compact city in key policy areas. Burton investigates perhaps the least explored aspect of sustainability, social equity, and finds that it is affected by urban form, but that the merits of the compact city remain unproved: urban compactness appears to promote social equity in some respects, but not in others. Also, certain aspects of compactness seem to be more beneficial to social equity than others, and some benefits are emerging in response to re-urbanisation and development of previously derelict land. Overall, cities with a greater mix of uses tend to be the most egalitarian, in that the effects of compactness benefit the advantaged and disadvantaged equally. Williams takes a holistic look at the aims and outcomes of urban intensification policies in England. Her research investigates urban intensification in three London boroughs over a ten-year period, to assess whether the benefits stated in planning policies have happened ‘on the ground’. It finds that policies have been effective for some purposes, such as using land in a sustainable way, but not for others - there were no noticeable effects on travel patterns or social conditions. Marked differences in impact between residential suburbs and mixed-use centres were also found. Although these findings support many of the key aims of intensification policies, there are also worrying policy failures. Both Burton's and Williams' research sheds new light on the relationship between urban form and some of its claimed impacts. They also reveal the dangerous simplicity of previous definitions of compactness.

The relative sustainability of different urban forms is addressed in the next four chapters. They present comparative research which tests different aspects of urban form against a range of sustainability variables. This research covers spatial scales from the city, to the neighbourhood and to the individual house. Newton reports on the environmental sustainability of alternative urban forms in Australia. He looks beyond the traditional distinction between dispersed and compact city, and adds' edge city', ‘corridor city’ and ‘fringe city’. The research, based on modelling techniques, supports the merits of the compact city and its close variants over a ‘business as usual’ scenario. Buxton also reviews the current debate in Australia on preferred urban form in terms of transport and energy use. In this instance, ‘urban selfcontainment’ is introduced as an alternative to the dispersed or compact forms, in a model allied to New Urbanism's idea of urban villages. The sustainability of different neighbourhoods in Scotland is investigated by Masnavi - with density and mix of uses as variables. The study reports on behaviour and attitudes of residents in terms of travel patterns, social interaction and perceptions of quality of the environment. Newton et al take the investigation down to the scale of the individual building. They question the sustainability of the preferred Australian housing type - the detached house on its own parcel of land - and review the difference between mid-density and low-density detached forms in terms of energy and greenhouse gases.

In the above chapters the issue of urban ecosystems is hardly mentioned. Yet it is a key component of urban sustainability. This omission is redressed by Alberti, who offers a thorough review of possible effects of urban form on ecosystems. She states that ‘Land use is one of the most important factors influencing ecological processes and biodiversity, but there is little understanding of how urban form affects ecosystem dynamics’. She goes on to clarify some of the mechanisms behind the relationships between spatial patterns and ecological processes and suggests key directions for future research.

Finally, Scofham and Marat-Mendes present research on an aspect of urban form that is rarely discussed in the sustainability debate: that of the ability of different urban forms to adapt over time. The authors look to historical precedent to identify physical qualities or ‘ground rules’ of urban form that allow adaptability to be achieved. They conclude that space is the asset that permits change to occur progressively and gradually, and that there is a consistency in historical precedents in the shape and size of the urban grid that adapts well to change. Their research adds to the debate by providing recommendations in terms of specific dimensions and shapes. In combination, these chapters provide valuable insights into a range of elements of sustainable urban form. When taken together, they do not enable the formation of a ‘blueprint’ for city form in the future, but they do challenge existing wisdom, and show how simplistic assumptions made in the past have been misleading. They also show how important it is to address the complexity of urban areas before drawing conclusions about their sustainability. Most of all though, they reveal the breadth of urban elements that either impact upon the sustainability of urban form, or are affected by it. Attempting to reconcile conflicts and trade-offs between these elements is the major challenge for those involved in managing the urban environment.

Simon Guy and Simon Marvin
Models and Pathways: The Diversity of Sustainable Urban Futures

Introduction

How do policy makers achieve the objective of building a sustainable urban future? This is the critical question that lies at the core of this book. We are not going to approach this question in a straight forward way. Instead, we want to tackle a number of assumptions that, we argue, hinder thinking about how sustainable cities can be achieved. In particular, we want to enlarge the concept of a sustainable city by building a more complex and multilayered understanding of what the city might become. While we cannot offer policy makers a simple model or pathway towards a sustainable city, we do begin to build a conceptual framework that acknowledges the multiplicity of pathways towards different sustainable futures that often co-exist within a single city. There are three stages to our argument.

First is the shift from the concept of a singular model towards multiple models of what the sustainable city might become. We question the emphasis that is placed on the achievement of sustainability through one model - compact urban form. It is not that we necessarily reject the notion that the physical re-ordering of the city can achieve environmental benefits, though even compact city advocates recognise that the evidence to support sustainability claims are complex and often contradictory. Rather, our concern is that the continued search for a simple and universal model of sustainable urban form can blind researchers and policy makers to the multiplicity of innovations that could each make a quite distinctive contribution towards the development of more sustainable urban futures. Instead, we argue that the compact city debate is perhaps best understood as one amongst a number of different models of what might actually constitute a sustainable city.

Second is the rejection of the simplistic use of models, and the development of competing pathways to sustainable cities. We are concerned that the notion of models is often used in an over deterministic way. Models are often used as straight forward blueprints to be translated into reality through physical planning and design policies in a series of linear stages. Instead, we argue that models should be used in a much softer, more flexible fashion. Rather than viewing models as specifications for a city, we argue that they are better employed as conceptual devices to sensitise us to different visions of what the sustainable city might become. We can, for instance, examine the extent to which the viewpoints and strategies of different urban actors, with often competing social, political and commercial interests, resonate or dissonate with the visions inscribed in particular models of development. In this sense, we can then build an understanding of how the changing social organisation of urban development may promote particular pathways towards distinct urban futures.

Third is the recognition that a wide diversity of sustainable urban futures are likely to coexist within a single city. In this context, we need to think differently about how the sustainable city could be achieved. Abandoning the search for a singular model, policy makers would chart the multiplicity of pathways towards what might be different sustainable futures. The challenge here is to examine the tensions and similarities between these pathways; in particular, focusing on the different social assumptions and biases built into them. We explore these competing strategies by reference to our own research into the management and development of electricity and water networks in the Newcastle Metropolitan region.

From singular to multiple models

Single model - the compact city discourse

We begin by highlighting a number of contradictions in the claims made for the compact city. A useful starting point here is the discussion and analysis set out in the preceding volume to this book which focuses the debate by asking whether the compact city can be considered a sustainable urban form (Jenks et al, 1996). We do not need...

Table of contents

• Cover Page
• Half Title page
• Title Page
• Copyright Page
• Contents
• Contributors
• Acknowledgements
• Achieving Sustainable Urban Form An Introduction
• Part 1 Defining Sustainable Urban Form
• Part 2 Urban Form and Transport: New Dimensions
• Part 3 Approaches and Strategies for Achieving Sustainable Urban Form
• Part 4 Built Form and Design Solutions
• References
• Index